Recorder



J. N. TUTTLE.

RECORDER.

APPLICATION FILED SEPT- 9, 1919- 1,406,507, Patented Feb. 14, 1922.

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momma Specification of Letter! Patent.

Patented Feb. 14, 19,22.

To all whom it may concern.-

" fication.

Be it knownthat, I, Jams N. Tu'rrm, a citizen of the United States,residing at Newton Center, in the county of Middlesex, State ofMassachusetts, have invented certain newand useful Improvements inRecorders, of which the-f0 lowing is a speci- This invention relates toa novel marking device, and a method used in connection with recordersfor securmg a legible record without the use of ink or punch marks. The

device that I have invented, it is to be understood, may be used uponany kmd of recorder since it is entirely immaterial ust what kind ofquantity is being measured by the instrument.

Another object is to eliminate all contact, and therefore allfrictionbetween the record sheet and the stylus cooperating therewith,and thus. insure accurate recording of the quantity measured.

Another object is to make the movable stylus as light in weight aspossible.

Other objects and advantages will be apparent as the description of theinvention proceeds. v v 1 In the accompanying drawing which illustratesmy invention there is shown a curve drawing instrument for recording thevoltage of an electric circuit. This particular kind of recordinginstrument is shown only by wayof example as my device may be installedon any other type of curve drawing instrument;

Fig. 1 is a pers ective view showing a general assembly 0 theinstrument, record sheet and stylus; Fig. 2 is an enlarged view inperspective showing the stylus and the record sheet; Figs. 3 and 4 aredetail views showing the manner in which the stylus is constructed.

Referring now more in detail to the drawings, in which like referencecharacters re-.

fer to like parts throughout, the voltmeter 12 is connected across thecircuit 11 to measure the voltage thereof. The connection is made bymeans of the terminal board 13. A resistance 14 is placed in series withthe voltmeter. The shaft 15 of the instrument is supported in suitablebearings, not shown. It is not deemed necesary to enter specificallyinto the structural details of the instrument 12, since these areimmaterial as far as my invention is concerned.

A record sheet 16 is driven at a uniform rate by suitable clock work,not shown. The

exposed surface ofthe record sheet is a propriatel ruled and calibratedso that the value of t e guantity measured may easily be ascertame atany point of the curve traced thereon. Appropriate marking means, suchas a stylus is adapted to be guided over' the surface of the recordsheet. To support the recording means a roller 18 is provided. Forming asupport for the roller 18 there are provided the posts 32 carried by astationary art 33 of the record sheet support. The ro ler 18' guides atube 17 carrying at its free extremity the marking stylus as it movesback and forth trans versely of the record sheet 16.

The hollow tube 17 is fastened to a transverse shaft 34 pivoted at itsends in the U shaped member 19 which in' turn is fas tened to the rod20. Said rod 20 is fastened to the shaft 15 of the instrument 12. As afurther support for the member 19, a hollow .rod 21 is provided, alsoconnected to the shaft 15. The tube 17 is plugged at its forward end bya short cylinder of insulating material 22 provided with a pair ofapertures for the reception of a thin wire 23. This thin wire forms aloop that extends outside of the tube, as clearly shown in Figs. 2 and3. The loop is formed V-shaped so as to provide a pointed stylus 24 andsaid stylus is bent so that its plane is perpendicular to the plane ofthe record sheet 16. The

tip 24' of the stylus is made of a proper kind of resistance metal so asto cause the tip to be heated at a passage of a current therethrough. Asclearly shown in Fig. 3, the tip 24' of the stylus clears the uppersurfaceof the record sheet 16 by an appreciable amount so that there canbe no friction between the record sheet and the stylus. The heat of thestylus is insuflicient to cause combustion of sheet 16.

A pair of leading-in wires 25 and 26 are electrically connected to theends of the 100 formed by the wire 23 and extend throug the hollow tube17 and also through the hollow tube 21. The wire 25 is electricallyconnected to the helical conductor 27 surrounding the shaft 15 of theinstrument 12; said conductor in turn is electrically connected to thestationary post 28. In a similar way the wire 26 is connected to theconductor 29 which in turn is connected to post 30. The

so that their combined 12. The posts 28 and 30 are connected by a pairof conductors to an appropriate ternnnal block '31, which, in turn,serves to connect the wires with the source of suppl 11. A spring 35,connected at its ends wltli members. 17 and 21, parts properly whenoperation. I The exposed surface of the record sheet serves to positionsaid the instrument 12 is in 16 is chemically. prepared with a solutionsensitive to heat. For example, in some of the devices I have tried Ihave successfully used for the sensitive medium a solution of normalcopper nitrate but it is of course to be understood that any othersolution which may be chemically altered the applica tion of heat may beused. he solution is applied to the surface, and when dry, said surfaceacquires a brownish stain if exposed to 'heat of a proper temperature,which temperature is considerably lower than that required to causecombustion of the sheet.

From the foregoing description of the apparatus, the operation of thedevice should be clear. As the voltmeter 12 responds to the variationsin the voltage of the electric circuit 11, the shaft 15 takes upcorrespondin positions agreeing with such vahe rods 20 and 21 connectedto in conjunction with parts'17, 19 the heated sheet 16. As the heatedst lus moves in close proximity to the sensitlzed surface, a chemicalreaction takes place due to the heat radiated from the tip of thestylus, and a stain is produced upon the paper accurately recording therelative movements of the stylus and sheet. It is to be noted that thestylus may be heated by any well known means besides the passage of anelectric current therethrough. The device is absolutely frictionlesssince the stylus is always out of contact with the sheet; at the sametime a fairly thin line is obtained for the record since the stylus isso formed that the heat is fairly well localized and that portion of therecord sheet only is altered which passes directly under the tip of thestylus.

tact therewith, means While I have shown one particular embodiment of myinvention, I do not wish to be limited thereto but desire to claim allmodi- 'fications falling fairly within the scope of my invention.

What I claim as new and desire to secure by etters Patent of theUnitedStates, is:

1'..In a recorder, relatively movable thereto and out of confor heatingsaid stylu's, said record sheet having a surface s'en-- sitive to theheat whereby a record is secured of the relative movement of the sheetand stylus.

2. In a recorder, a record sheet, a heated stylus relatively movablethereto, said sheet being out of contact with said stylus, and. having asurface stained without burning by the radiation of heat, where thestylus and the closest together. 7

3. In a recorder, a. record sheet, astylus relatively movable thereto,means-for passing an electric current through said stylus for heatingit, said sheet being out of contact with said stylus, and having achemicallysensitized surface affected by the radiation of heat from thestylus where it and the surface approagh closest together.

radiated by the sty u from the stylus surface approach I to be movedforward at a uniformrate, a" mechanical contact with said stylus out ofsheet, and adapted to be moved in accordance with a quantity to bemeasured, an electric circuit completed through said stylus for heatingit, said sheet having a surface passing in close proximity by theradiation of heat from the stylus where it and the surface approachclosest together. p 5. The method of producing a record, which consistsin making a surface of the record sheet sensitive to heat, bringing saidsheet directly under a movable stylus but out of contact therewith, andheating said stylus so as to affect that portion of the surfaceimmediately below said stylus.

In witness whereof, I have hereunto set my hand this fifth day. ofSeptember, 1919.

JAMES N TUTTLE.

to the stylus and bemg chemically sensitlzed so as to be colored arecordsheet, a stylus so

